Nucleosomes play a vital role in chromatin organization and gene regulation,acting as key hubs that inter-act with various chromatin-associated factors through diverse binding mechanisms.Recent research has highlighte...Nucleosomes play a vital role in chromatin organization and gene regulation,acting as key hubs that inter-act with various chromatin-associated factors through diverse binding mechanisms.Recent research has highlighted the prevalence of mutations in linker histones across different types of cancer,emphasizing their critical involvement in cancer progression.These cancer-associated mutations in linker histones have been shown to disrupt nucleosome stacking and the formation of higher-order chromatin structures,which in turn significantly affect epigenetic regulatory processes.In this review,we provide a comprehensive analysis of how cancer-associated linker histone mutations alter their physicochemical properties,influencing their binding to nucleosomes,and overall chromatin architecture.Additionally,we explore the significant impact of mutations near post-translational modification sites,which further modulate chromatin dynamics and regulatory functions,offering insights into their role in oncogenesis and potential therapeutic targets.展开更多
The Chinese Tianshan belt of the southern Altaids has undergone a complicated geological evolution. Different theories have been proposed to explain its evolution and these are still hotly debated. The major subductio...The Chinese Tianshan belt of the southern Altaids has undergone a complicated geological evolution. Different theories have been proposed to explain its evolution and these are still hotly debated. The major subduction polarity and the way of accretion are the main problems. Southward, northward subduction and multiple subduction models have been proposed. This study focuses on the structural geology of two of the main faults in the region, the South Tianshan Fault and the Nikolaev Line. The dip direction in the Muzhaerte valley is southward and lineations all point towards the NW. Two shear sense motions have been observed within both of these fault zones, a sinistral one, and a dextral one, the latter with an age of 236-251 Ma. Structural analyses on the fault zones show that subduction has been northward rather than southward. The two shear sense directions indicate that the Yili block was first dragged along towards the east due to the cloclkwise rotation of the Tarim block. After the Tarim block stopped rotating, the Yili block still kept going eastward, inducing the dextral shear senses within the fault zones.展开更多
The distribution and genesis of secondary pores in Paleogene clastic reservoirs of Beidagang structural belt in the Huanghua depression have been systematically studied.We investigated sedimentary facies and carried o...The distribution and genesis of secondary pores in Paleogene clastic reservoirs of Beidagang structural belt in the Huanghua depression have been systematically studied.We investigated sedimentary facies and carried out a comprehensive analy-sis of the vast amount of data from casting thin sections,scanning electron microscope and physical data.Then we analyzed the pore types,pore evolution,distribution and genesis of secondary pores in our study area and discussed the factors controlling the distribution of secondary pores.The results show that pores in the study area are largely composed of intergranular dissolution pores and constituent dissolved pores.Three secondary pore zones were developed in the study area at depths of 2800~3400 m,3600~4200 m and 4500~4800 m.Secondary pores have been formed mainly because carbonate cement,feldspar,clastic debris and other plastic substances were dissolved by organic acid,released during the evolution of organic matter and acid water formed by CO2.The development and distribution of secondary pores are vertically controlled by the maturity time of source rocks and hori-zontally by the distribution of acid water.As well,this distribution was affected by the sedimentary facies belt and the development of fault zones.展开更多
Objective：To investigate the effect of hepatitis C virus non-structural protein 4B（HCV NS4B） on c-Myc, P53, ras gene expression＂ and apoptosis in hepatic cells and study the possible role that NS4B played in the c...Objective：To investigate the effect of hepatitis C virus non-structural protein 4B（HCV NS4B） on c-Myc, P53, ras gene expression＂ and apoptosis in hepatic cells and study the possible role that NS4B played in the carcinogenesis of heparoma. Methods： The recombinant plasmid（PCXN2-NS4B, PCXN2-P53） and the empty, vector were transfected or co-transfected into Chang liver cells with liposome. Screening was performed with G418. Plasmid mRNA was detected by RT-PCR. The pro rein expressions of c-Myc and ras genes were analyzed by immunocytochemistry. The expressions of wild-type P53 （wtp53） gene were detected by in situ hybridization. TUNEL（flow cytometry） was used for assessing the rate of apoptosis. Results：No expression of c-Myc gene was found in PCXN2 group. The expression of c-Myc gene in NS4B group was 21.3% ＋ 1.2%. The ex pression of ras gene in PCXN2 group was lower than that in NS4B group. Compared with PCXN2 group, the expression of P53 mRNA was not promoted or inhibited in NS4B group. But the expression of P53 mRNA in NS4B-P53 group was lower than that in P53 group. In PCXN2, NS4B, P53 and NS4B-P53 group, the rates of apoptosis were 17.02% ± 1.24%, 11.94% ± 2.24%, 25.84% ± 3.49% and 18.34% ± 1.55% respectively. Conclusion ：HCV NS4B induces the expression of c-Myc and ras gene. HCV NS4B may play a role in the inhibition of cell death through P53-dependent manner. Results from this study suggested that HCV NS4B might contribute to the viral carcinogenesis.展开更多
Based on the results from seismogeological study, aeromagnetic inversion and deep seismic sounding (DSS), it is found that the M8.0 earthquakes in North China have three common deep structural characteristics, i.e., t...Based on the results from seismogeological study, aeromagnetic inversion and deep seismic sounding (DSS), it is found that the M8.0 earthquakes in North China have three common deep structural characteristics, i.e., they all took place above the ultra-crustal deep faults or on the edges of the tectonic blocks with higher intensity, and there are low-velocity, low-density and high-conductive layers deep in the epicentral regions. The origins of the earth-quakes are also discussed and the two possibilities of seismogenesis are proposed, i.e., tectonic movement and intracrustal explosion.展开更多
Wild-type potato (Solanum tuberosum L.) plants and their transformants harboring agrobacterial rolB or rolC genes under control of the patatin class I promoter were cultured in vitro. These plants were used as a sourc...Wild-type potato (Solanum tuberosum L.) plants and their transformants harboring agrobacterial rolB or rolC genes under control of the patatin class I promoter were cultured in vitro. These plants were used as a source of single-node stem cuttings. The structure of native starch in tubers formed on cuttings was determined using methods of X-ray scattering and differential scanning microcalorimetry (DSC). It was found that in starch from tubers of rolB plants the melting temperature of crystalline lamella was lower and their thickness was less than that in wild-type potato. In tubers of rolC plants starch differed from starch in wild-type plants by a higher melting temperature, reduced melting enthalpy, and a greater thickness of crystalline lamellae. The melting of starch from tubers of rolC plants proceeded as the melting of two independent crystalline structures with melting temperatures of 338.0°K and 342.8°K. Overall data show that starches of different structure can be obtained by using transgenic approach.展开更多
[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from ...[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase（katA）gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites（Ser95,Thr96,Ser241,Ser242,Thr281,Ser338）,four conserved residues（Ser95,His216,Tyr281,Asp341）and two active sites（His56,Asn129）were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase（PDB：2ISA_A）of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene.展开更多
This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes（PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UF...This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes（PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UFGT,OMT and GST） related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to4 weeks after flowering（WAF）, down-regulated from6 WAF to veraison, whereas DFR was up-regulated at8 WAF, and then up-regulated from veraison to maturity.CHS3, F3050 H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins, and between F3050 H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F30 H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F30 H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F30 H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.展开更多
Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associa...Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associated with structural degradation and side reactions during electrochemical cycling.Herein,we demonstrate the possibility of preparing NRCs,typically Li Ni_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9055),with much-improved mechanical and chemical stability based on the surface coating of the hydroxide precursors.Specifically,a conformal nanoshell containing both Al^(3+)and W^(6+)was first deposited around the precursor particles,and the following high-temperature lithiation produced the targeted NCM9055 with favorable structural features,where Al3+existed as a bulk dopant to enhance the structural stability while the high-valent W^(6+)promoted the microstructural evolution into radially-architectured elongated primary particles.Such a structural engineering benefiting from the Al^(3+)/W^(6+)co-modification endowed the prepared NCM9055 cathode(NCM9055-Al W)with much-improved cycling stability,as revealed by a high-capacity retention of 98.0%after 100 cycles(tested at 0.5 C,4.3 V)as compared to only 79.0%for the pristine cathode without Al^(3+)/W^(6+).The NCM9055-15Al W cathode also showed a high-rate capability with extraordinary structural stability against mechanical failure.Our study highlighted the enormous potential of precursor multi-element treatment as an effective tool in structural refinement of NRCs to circumvent their stability challenge for their applications in high-energy LIBs.展开更多
Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling pha...Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.展开更多
Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in...Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in enduring neurological deficits.Recent findings from our research indicate that inhibition of Rho-associated kinase(ROCK)2 facilitates neuroprotection in different models of central nervous system diseases.In addition,our prior studies have demonstrated that axonal protection enhances the regeneration of injured axons.However,it remains unclear whether the axonal protection mediated by ROCK2 inhibition also facilitates synaptogenesis.In this study,we aimed to investigate the effects of inhibiting ROCK2 expression on synaptogenesis and neurogenesis in ischemic stroke using an shRNA-expressing adeno-associated virus(AAV)vector(AAV-sh.ROCK2).We demonstrated that AAV-sh.ROCK2 increased neurite outgrowth and facilitated synaptogenesis in vivo.Furthermore,AAV-sh.ROCK2 increased neuronal survival and promoted neurogenesis following middle cerebral artery occlusion surgery as well as long-term motor functional recovery after ischemia/reperfusion injury.Notably,AAV-sh.ROCK2 also stimulated serotonergic and dopaminergic axon sprouting after ischemia/reperfusion injury.Mechanistically,AAV-sh.ROCK2 activity resulted in increased anti-collapsin response mediator protein 2 activation and reductions in RhoA and ROCK2 expression.Our study identified ROCK2 as a critical regulator of synaptogenesis and neurogenesis,highlighting it as a promising target to facilitate neuroprotection and regeneration in ischemic stroke.展开更多
A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an or...A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an orally administered nanogene delivery system.Designed to achieve in situ,efficient delivery of chimeric antigen receptor(CAR)genes to tumor sites,this approach offers a novel strategy for CAR-macrophage(CAR-M)based immunotherapy.Its key highlights are as follows.展开更多
Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their un...Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their unique dimensions and structures.Unfortunately,emerging evidence suggests that NMs may facilitate the transmission of ARGs.It is crucial to elucidate how NMs affect the evolution and dissemination of ARGs.The current review comprehensively examines the role of NMs in the widespread transmission of ARGs in aquatic environments and the underlying mechanisms involved in the process.It aims to clarify the effects and mechanisms of NMs on the horizontal gene transfer processes that are associated with ARGs,including the enhancement of cell membrane permeability,the formation of nanopores on membranes,promotion of mutagenesis,and the generation of reactive oxygen species(ROSs).Furthermore,the trade-off between the removal of ARGs and horizontal transfer has been elucidated.The review aspires to guide future research directions,advance knowledge on the implications of NMs in the field of ARGs' transmission,and provide a theoretical foundation for the development of safer and more effective applications of NMs.展开更多
AIM:To identify key genes and inflammatory signaling pathways involved in the anti-inflammatory effects of Hedysarum polybotrys polysaccharide(HPS)in a rat model of endotoxin-induced uveitis(EIU).METHODS:EIU was induc...AIM:To identify key genes and inflammatory signaling pathways involved in the anti-inflammatory effects of Hedysarum polybotrys polysaccharide(HPS)in a rat model of endotoxin-induced uveitis(EIU).METHODS:EIU was induced in Wistar rats through subcutaneous injection of lipopolysaccharide(LPS,200μg)and the rats were then randomly assigned to EIU group(n=5)and the HPS intervention group(n=5).HPS(400 mg/kg,intraperitoneally)or its carrier was administered 24h and 1h prior to EIU induction.Eyes were examined and enucleated 24h post-induction,and total RNA was extracted from the iris-ciliary body.Gene expression microarrays were used to identify differentially expressed genes(DEGs),followed by bioinformatics analyses,including gene ontology(GO)and pathway analysis.Key findings were not experimentally validated at the mRNA or protein level.RESULTS:A total of 322 DEGs were identified,comprising 254 mRNA and 68 lncRNA genes.GO analysis revealed significant functional categories,including response to LPS.Pathway analysis identified key signaling pathways involved in uveitis,such as cytokine-cytokine receptor interactions.Notably,16 mRNA and 7 lncRNA DEGs emerged as central nodes in the gene correlation network.CONCLUSION:HPS exerts its anti-inflammatory effects through coordinated signaling pathways,offering insights into potential therapeutic targets for managing uveitis.展开更多
Aspergillus species are ubiquitous fungi that produce mycotoxins(secondary metabolites)known as sterigmatocystin and aflatoxins in many different kinds of foods,which leads to serious contamination in agricultural pro...Aspergillus species are ubiquitous fungi that produce mycotoxins(secondary metabolites)known as sterigmatocystin and aflatoxins in many different kinds of foods,which leads to serious contamination in agricultural products,thereby endangering human health.Extensive studies on Aspergillus fungi have been conducted on growth and development,aflatoxin biosynthesis,and their interactions with environment.Here,we summarized a series of functional genes of the main Aspergillus fungi relative to toxins occurrence in foods,which revealed the signal transduction mechanisms of their involvement in growth and development,toxin production,and response to light,anticipating providing theoretical guidance on developing control and prevention technologies for mycotoxin contamination in agricultural products to ensure food safety.展开更多
Insects represent one of the most evolutionarily successful groups,with their diversity hypothesized to be related to the regulatory roles of Hox genes,a set of related genes encoding homeodomain transcription factors...Insects represent one of the most evolutionarily successful groups,with their diversity hypothesized to be related to the regulatory roles of Hox genes,a set of related genes encoding homeodomain transcription factors determining the identity of segments along the anterior-posterior axis of the embryo.However,functional insights into the roles of Hox genes in primitive ametabolous insects,which represent the critical transition from aquatic crustaceans to winged insects,have been limited.In this study,we identified complete protein-coding sequences of 10 Hox genes in the Zygentoma Thermobia domestica,and applied clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas 9)mediated gene knockout(KO)to decipher their functions.We found that the roles of pb,Dfd,and Scr are vital in specifying the appendages of the head in T.domestica,and these roles are relatively conserved in crustaceans and winged insects.Antp is essential for the development of the prothorax segment and the first pair of legs in T.domestica.Ubx and abd-A fully repress appendage development in the abdomen of T.domestica,which implies a functional switch from crustaceans to insects.Additionally,the role of ftz in segmenting the abdomen of T.domestica suggests it has acquired new functions in primitive insects,beyond its traditional Hox-like roles.Although KOs of lab,Hox3,and Abd-B did not result in obvious external phenotypic changes,they led to a significant decrease in hatching rates and substantial deviations in daily survival numbers compared to the negative control.These findings underscore the indispensable roles of all Hox genes during the embryonic development of T.domestica.Our study sheds new light on the functional evolution of Hox genes in ametabolous insects and enhances our understanding of the genetic underpinnings of insect development and diversification.展开更多
From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global he...From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global health.OVER the past 40 years,one man has distinguished himself through a deep commitment to researching protein structures of high pathogenic viruses,and published numerous significant works in top international scientific journals.展开更多
Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to conce...Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to concentration quenching has become a key research focus.In this work,we successfully synthesized KBi(MoO_(4))_(2):x Tb^(3+)(x=0-100 at%)(denoted as KBM:x Tb^(3+))phosphors via a high-temperature solid-state reaction.Remarkably,no concentration quenching was observed across the entire doping range.This anti-quenching behavior originates from the large Tb^(3+)-Tb^(3+)interionic distance(>5Å)inherent to the quasi-layered crystal structure,which effectively suppresses multipole-interaction-mediated energy migration.At full Tb^(3+)substitution(x=100 at%),the material undergoes a structural phase transition from the monoclinic KBM phase to the triclinicα-KTb(MoO_(4))_(2)(α-KTM)phase.Theα-KTM phosphor exhibits excellent thermal stability(activation energy=0.6129 eV)and a single-exponential decay profile,whereas KBM:x Tb^(3+)(x<100%)display double-exponential decay behaviors,attributed to dual energy transfer pathways.These findings provide new insights into the luminescence mechanisms of high-concentration rare-earth-doped systems and offer guidance for designing nextgeneration anti-quenching phosphors.展开更多
Antibiotic contamination has garnered significant attention,particularly given the growing pressures from aquaculture,a key contributor to environmental antibiotic loads.Addressing both antibiotic and nitrogen polluti...Antibiotic contamination has garnered significant attention,particularly given the growing pressures from aquaculture,a key contributor to environmental antibiotic loads.Addressing both antibiotic and nitrogen pollution in such ecosystems is critical.In this study,the aerobic denitrifying bacterium Marinobacter hydrocarbonoclasticus RAD-2,previously isolated in our laboratory,was subjected to a series of concentration gradients(0,20,40,60,80,100 mg/L)to evaluate the single and combined effects of tetracycline(TET)and chlortetracycline(CTC)on the aerobic denitrification process.Among them,the combined effects of antibiotics were set up in a full-factor experimental design(a total of 30 treatment combinations)on the basis of the single-factor experiments of TET and CTC.Results demonstrated that the inhibitory impact of both antibiotics intensified with increasing concentration,with CTC exerting a more pronounced inhibitory effect.Notably,RAD-2 was unable to proliferate at 100 mg/L of TET or 80 mg/L of CTC.High concentrations of either antibiotic significantly suppressed the expression of key denitrification functional genes,including nirX,napA,norB,and nosZ.Furthermore,simultaneous exposure to both antibiotics led to a rapid decline in nitrogen removal efficiency(TET or CTC>60 mg/L),alongside substantial inhibition of bacterial growth and functional gene expression,except for napA.Under specific concentration ranges,the combination of TET and CTC exhibits a certain degree of antagonistic effect.These findings provide critical insights into the restoration of wetland ecosystem health and inform strategies to mitigate the dual challenges of antibiotic and nitrogen pollution in aquaculture effluents.展开更多
Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastom...Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.展开更多
基金supported by the National Natural Science Foundation of China(No.12205112)financially supported by self-determined research funds of CCNU from the colleges’basic research and operation of MOE(CCNU24JC012)supported by Natural Science Foundation of Wuhan(No.2024040801020302).
文摘Nucleosomes play a vital role in chromatin organization and gene regulation,acting as key hubs that inter-act with various chromatin-associated factors through diverse binding mechanisms.Recent research has highlighted the prevalence of mutations in linker histones across different types of cancer,emphasizing their critical involvement in cancer progression.These cancer-associated mutations in linker histones have been shown to disrupt nucleosome stacking and the formation of higher-order chromatin structures,which in turn significantly affect epigenetic regulatory processes.In this review,we provide a comprehensive analysis of how cancer-associated linker histone mutations alter their physicochemical properties,influencing their binding to nucleosomes,and overall chromatin architecture.Additionally,we explore the significant impact of mutations near post-translational modification sites,which further modulate chromatin dynamics and regulatory functions,offering insights into their role in oncogenesis and potential therapeutic targets.
基金supported by the Chinese Major State Basic Research Program (Grants Nos.2009CB825007,2007CB411307)National Natural Science Foundation of China(Grant Nos.40730314,40821002, 41230207,41390441,41190075)the Molengraaff Fund to MCS
文摘The Chinese Tianshan belt of the southern Altaids has undergone a complicated geological evolution. Different theories have been proposed to explain its evolution and these are still hotly debated. The major subduction polarity and the way of accretion are the main problems. Southward, northward subduction and multiple subduction models have been proposed. This study focuses on the structural geology of two of the main faults in the region, the South Tianshan Fault and the Nikolaev Line. The dip direction in the Muzhaerte valley is southward and lineations all point towards the NW. Two shear sense motions have been observed within both of these fault zones, a sinistral one, and a dextral one, the latter with an age of 236-251 Ma. Structural analyses on the fault zones show that subduction has been northward rather than southward. The two shear sense directions indicate that the Yili block was first dragged along towards the east due to the cloclkwise rotation of the Tarim block. After the Tarim block stopped rotating, the Yili block still kept going eastward, inducing the dextral shear senses within the fault zones.
基金Financial support for this study by the National Basic Research Program of China(973)(No.2006CB 202300)is gratefully acknowledged
文摘The distribution and genesis of secondary pores in Paleogene clastic reservoirs of Beidagang structural belt in the Huanghua depression have been systematically studied.We investigated sedimentary facies and carried out a comprehensive analy-sis of the vast amount of data from casting thin sections,scanning electron microscope and physical data.Then we analyzed the pore types,pore evolution,distribution and genesis of secondary pores in our study area and discussed the factors controlling the distribution of secondary pores.The results show that pores in the study area are largely composed of intergranular dissolution pores and constituent dissolved pores.Three secondary pore zones were developed in the study area at depths of 2800~3400 m,3600~4200 m and 4500~4800 m.Secondary pores have been formed mainly because carbonate cement,feldspar,clastic debris and other plastic substances were dissolved by organic acid,released during the evolution of organic matter and acid water formed by CO2.The development and distribution of secondary pores are vertically controlled by the maturity time of source rocks and hori-zontally by the distribution of acid water.As well,this distribution was affected by the sedimentary facies belt and the development of fault zones.
基金Scientific Research Fund of Sichuan Provincial Education Department(20003531)
文摘Objective：To investigate the effect of hepatitis C virus non-structural protein 4B（HCV NS4B） on c-Myc, P53, ras gene expression＂ and apoptosis in hepatic cells and study the possible role that NS4B played in the carcinogenesis of heparoma. Methods： The recombinant plasmid（PCXN2-NS4B, PCXN2-P53） and the empty, vector were transfected or co-transfected into Chang liver cells with liposome. Screening was performed with G418. Plasmid mRNA was detected by RT-PCR. The pro rein expressions of c-Myc and ras genes were analyzed by immunocytochemistry. The expressions of wild-type P53 （wtp53） gene were detected by in situ hybridization. TUNEL（flow cytometry） was used for assessing the rate of apoptosis. Results：No expression of c-Myc gene was found in PCXN2 group. The expression of c-Myc gene in NS4B group was 21.3% ＋ 1.2%. The ex pression of ras gene in PCXN2 group was lower than that in NS4B group. Compared with PCXN2 group, the expression of P53 mRNA was not promoted or inhibited in NS4B group. But the expression of P53 mRNA in NS4B-P53 group was lower than that in P53 group. In PCXN2, NS4B, P53 and NS4B-P53 group, the rates of apoptosis were 17.02% ± 1.24%, 11.94% ± 2.24%, 25.84% ± 3.49% and 18.34% ± 1.55% respectively. Conclusion ：HCV NS4B induces the expression of c-Myc and ras gene. HCV NS4B may play a role in the inhibition of cell death through P53-dependent manner. Results from this study suggested that HCV NS4B might contribute to the viral carcinogenesis.
基金State Natural Science Foundation of China (4977230).
文摘Based on the results from seismogeological study, aeromagnetic inversion and deep seismic sounding (DSS), it is found that the M8.0 earthquakes in North China have three common deep structural characteristics, i.e., they all took place above the ultra-crustal deep faults or on the edges of the tectonic blocks with higher intensity, and there are low-velocity, low-density and high-conductive layers deep in the epicentral regions. The origins of the earth-quakes are also discussed and the two possibilities of seismogenesis are proposed, i.e., tectonic movement and intracrustal explosion.
文摘Wild-type potato (Solanum tuberosum L.) plants and their transformants harboring agrobacterial rolB or rolC genes under control of the patatin class I promoter were cultured in vitro. These plants were used as a source of single-node stem cuttings. The structure of native starch in tubers formed on cuttings was determined using methods of X-ray scattering and differential scanning microcalorimetry (DSC). It was found that in starch from tubers of rolB plants the melting temperature of crystalline lamella was lower and their thickness was less than that in wild-type potato. In tubers of rolC plants starch differed from starch in wild-type plants by a higher melting temperature, reduced melting enthalpy, and a greater thickness of crystalline lamellae. The melting of starch from tubers of rolC plants proceeded as the melting of two independent crystalline structures with melting temperatures of 338.0°K and 342.8°K. Overall data show that starches of different structure can be obtained by using transgenic approach.
基金Supported by the National Natural Science Foundation of China (No.31272692,No.30800847)
文摘[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase（katA）gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites（Ser95,Thr96,Ser241,Ser242,Thr281,Ser338）,four conserved residues（Ser95,His216,Tyr281,Asp341）and two active sites（His56,Asn129）were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase（PDB：2ISA_A）of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene.
基金supported by China Agriculture Research System(CARS-30)Jilin Agricultural Science and Technology College seed fund project(2013-903)
文摘This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes（PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UFGT,OMT and GST） related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to4 weeks after flowering（WAF）, down-regulated from6 WAF to veraison, whereas DFR was up-regulated at8 WAF, and then up-regulated from veraison to maturity.CHS3, F3050 H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins, and between F3050 H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F30 H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F30 H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F30 H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.
基金supported by the National Key R&D Program of China(Grant No.2022YFB2404402)the National Natural Science Foundation of China(Grant Nos.22025507,22421001,and 22409200)+1 种基金the Strategic Priority Research Program of the Chinese Academy of SciencesGrant No.XDB 1040200。
文摘Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associated with structural degradation and side reactions during electrochemical cycling.Herein,we demonstrate the possibility of preparing NRCs,typically Li Ni_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9055),with much-improved mechanical and chemical stability based on the surface coating of the hydroxide precursors.Specifically,a conformal nanoshell containing both Al^(3+)and W^(6+)was first deposited around the precursor particles,and the following high-temperature lithiation produced the targeted NCM9055 with favorable structural features,where Al3+existed as a bulk dopant to enhance the structural stability while the high-valent W^(6+)promoted the microstructural evolution into radially-architectured elongated primary particles.Such a structural engineering benefiting from the Al^(3+)/W^(6+)co-modification endowed the prepared NCM9055 cathode(NCM9055-Al W)with much-improved cycling stability,as revealed by a high-capacity retention of 98.0%after 100 cycles(tested at 0.5 C,4.3 V)as compared to only 79.0%for the pristine cathode without Al^(3+)/W^(6+).The NCM9055-15Al W cathode also showed a high-rate capability with extraordinary structural stability against mechanical failure.Our study highlighted the enormous potential of precursor multi-element treatment as an effective tool in structural refinement of NRCs to circumvent their stability challenge for their applications in high-energy LIBs.
基金supported by the National Natural Science Foundation of China (Grant Nos.92477128,92580137,92477205,12374200,11604063,11974422,and 12104504)the National Key R&D Program of China (MOST) (Grant No.2023YFA1406500)+3 种基金the Strategic Priority Research Program (Chinese Academy of Sciences,CAS) (Grant No.XDB30000000)the Fundamental Research Funds for the Central Universities and Research Funds of Renmin University of China (Grant No.21XNLG27)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2023 of the Renmin University of Chinaan outcome of “Two-dimensional anisotropic series of materials FePd2+xTe2:a structural modulation study from the atomic scale to the mesoscopic scale” (RUC25QSDL128),funded by the “Qiushi Academic-Dongliang” Talent Cultivation Project at Renmin University of China in 2025。
文摘Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.
基金supported by the National Natural Science Foundation of China,No.82471327the Natural Science Foundation of ShandongProvince,No.ZR2024MH200(both to SL).
文摘Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in enduring neurological deficits.Recent findings from our research indicate that inhibition of Rho-associated kinase(ROCK)2 facilitates neuroprotection in different models of central nervous system diseases.In addition,our prior studies have demonstrated that axonal protection enhances the regeneration of injured axons.However,it remains unclear whether the axonal protection mediated by ROCK2 inhibition also facilitates synaptogenesis.In this study,we aimed to investigate the effects of inhibiting ROCK2 expression on synaptogenesis and neurogenesis in ischemic stroke using an shRNA-expressing adeno-associated virus(AAV)vector(AAV-sh.ROCK2).We demonstrated that AAV-sh.ROCK2 increased neurite outgrowth and facilitated synaptogenesis in vivo.Furthermore,AAV-sh.ROCK2 increased neuronal survival and promoted neurogenesis following middle cerebral artery occlusion surgery as well as long-term motor functional recovery after ischemia/reperfusion injury.Notably,AAV-sh.ROCK2 also stimulated serotonergic and dopaminergic axon sprouting after ischemia/reperfusion injury.Mechanistically,AAV-sh.ROCK2 activity resulted in increased anti-collapsin response mediator protein 2 activation and reductions in RhoA and ROCK2 expression.Our study identified ROCK2 as a critical regulator of synaptogenesis and neurogenesis,highlighting it as a promising target to facilitate neuroprotection and regeneration in ischemic stroke.
文摘A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an orally administered nanogene delivery system.Designed to achieve in situ,efficient delivery of chimeric antigen receptor(CAR)genes to tumor sites,this approach offers a novel strategy for CAR-macrophage(CAR-M)based immunotherapy.Its key highlights are as follows.
基金supported by the State Key Laboratory of Urban Water Resource and Environment (Harbin Institute of Technology) (No.2022TS13)the key projects of National Natural Science Foundation of China (No.2019YFC0408503)the Key Research Program of Wuhan (No.2022022202015015)。
文摘Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their unique dimensions and structures.Unfortunately,emerging evidence suggests that NMs may facilitate the transmission of ARGs.It is crucial to elucidate how NMs affect the evolution and dissemination of ARGs.The current review comprehensively examines the role of NMs in the widespread transmission of ARGs in aquatic environments and the underlying mechanisms involved in the process.It aims to clarify the effects and mechanisms of NMs on the horizontal gene transfer processes that are associated with ARGs,including the enhancement of cell membrane permeability,the formation of nanopores on membranes,promotion of mutagenesis,and the generation of reactive oxygen species(ROSs).Furthermore,the trade-off between the removal of ARGs and horizontal transfer has been elucidated.The review aspires to guide future research directions,advance knowledge on the implications of NMs in the field of ARGs' transmission,and provide a theoretical foundation for the development of safer and more effective applications of NMs.
基金Supported by the National Natural Science Fundation of China(No.82101107No.81471575).
文摘AIM:To identify key genes and inflammatory signaling pathways involved in the anti-inflammatory effects of Hedysarum polybotrys polysaccharide(HPS)in a rat model of endotoxin-induced uveitis(EIU).METHODS:EIU was induced in Wistar rats through subcutaneous injection of lipopolysaccharide(LPS,200μg)and the rats were then randomly assigned to EIU group(n=5)and the HPS intervention group(n=5).HPS(400 mg/kg,intraperitoneally)or its carrier was administered 24h and 1h prior to EIU induction.Eyes were examined and enucleated 24h post-induction,and total RNA was extracted from the iris-ciliary body.Gene expression microarrays were used to identify differentially expressed genes(DEGs),followed by bioinformatics analyses,including gene ontology(GO)and pathway analysis.Key findings were not experimentally validated at the mRNA or protein level.RESULTS:A total of 322 DEGs were identified,comprising 254 mRNA and 68 lncRNA genes.GO analysis revealed significant functional categories,including response to LPS.Pathway analysis identified key signaling pathways involved in uveitis,such as cytokine-cytokine receptor interactions.Notably,16 mRNA and 7 lncRNA DEGs emerged as central nodes in the gene correlation network.CONCLUSION:HPS exerts its anti-inflammatory effects through coordinated signaling pathways,offering insights into potential therapeutic targets for managing uveitis.
基金supported by the key project of National Natural Sciences Foundation of China(U22A20551,32030085)the Major Project of Hubei Hongshan Laboratory,China(2021hszd015)+2 种基金the Hubei Province Major Science and Technology Special Project,China(2023BBA002)the National Natural Sciences Foundation of China(U22A20551)the National Natural Science Foundation of China Excellent Youth Fund(32422072)。
文摘Aspergillus species are ubiquitous fungi that produce mycotoxins(secondary metabolites)known as sterigmatocystin and aflatoxins in many different kinds of foods,which leads to serious contamination in agricultural products,thereby endangering human health.Extensive studies on Aspergillus fungi have been conducted on growth and development,aflatoxin biosynthesis,and their interactions with environment.Here,we summarized a series of functional genes of the main Aspergillus fungi relative to toxins occurrence in foods,which revealed the signal transduction mechanisms of their involvement in growth and development,toxin production,and response to light,anticipating providing theoretical guidance on developing control and prevention technologies for mycotoxin contamination in agricultural products to ensure food safety.
基金National Natural Science Foundation of China(Nos.32170425,32470443,32300388).
文摘Insects represent one of the most evolutionarily successful groups,with their diversity hypothesized to be related to the regulatory roles of Hox genes,a set of related genes encoding homeodomain transcription factors determining the identity of segments along the anterior-posterior axis of the embryo.However,functional insights into the roles of Hox genes in primitive ametabolous insects,which represent the critical transition from aquatic crustaceans to winged insects,have been limited.In this study,we identified complete protein-coding sequences of 10 Hox genes in the Zygentoma Thermobia domestica,and applied clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas 9)mediated gene knockout(KO)to decipher their functions.We found that the roles of pb,Dfd,and Scr are vital in specifying the appendages of the head in T.domestica,and these roles are relatively conserved in crustaceans and winged insects.Antp is essential for the development of the prothorax segment and the first pair of legs in T.domestica.Ubx and abd-A fully repress appendage development in the abdomen of T.domestica,which implies a functional switch from crustaceans to insects.Additionally,the role of ftz in segmenting the abdomen of T.domestica suggests it has acquired new functions in primitive insects,beyond its traditional Hox-like roles.Although KOs of lab,Hox3,and Abd-B did not result in obvious external phenotypic changes,they led to a significant decrease in hatching rates and substantial deviations in daily survival numbers compared to the negative control.These findings underscore the indispensable roles of all Hox genes during the embryonic development of T.domestica.Our study sheds new light on the functional evolution of Hox genes in ametabolous insects and enhances our understanding of the genetic underpinnings of insect development and diversification.
文摘From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global health.OVER the past 40 years,one man has distinguished himself through a deep commitment to researching protein structures of high pathogenic viruses,and published numerous significant works in top international scientific journals.
基金supported by the Natural Science Research Project of Anhui Province Education Department for Excellent Young Scholars(Grant No.2024AH030007)the National Natural Science Foundation of China(Grant No.52202001)。
文摘Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to concentration quenching has become a key research focus.In this work,we successfully synthesized KBi(MoO_(4))_(2):x Tb^(3+)(x=0-100 at%)(denoted as KBM:x Tb^(3+))phosphors via a high-temperature solid-state reaction.Remarkably,no concentration quenching was observed across the entire doping range.This anti-quenching behavior originates from the large Tb^(3+)-Tb^(3+)interionic distance(>5Å)inherent to the quasi-layered crystal structure,which effectively suppresses multipole-interaction-mediated energy migration.At full Tb^(3+)substitution(x=100 at%),the material undergoes a structural phase transition from the monoclinic KBM phase to the triclinicα-KTb(MoO_(4))_(2)(α-KTM)phase.Theα-KTM phosphor exhibits excellent thermal stability(activation energy=0.6129 eV)and a single-exponential decay profile,whereas KBM:x Tb^(3+)(x<100%)display double-exponential decay behaviors,attributed to dual energy transfer pathways.These findings provide new insights into the luminescence mechanisms of high-concentration rare-earth-doped systems and offer guidance for designing nextgeneration anti-quenching phosphors.
基金supported by the Science Fund for Distinguished Young Scholars of Zhejiang Province(No.LR22C190001)the National Natural Science Foundation of China(No.41401556).
文摘Antibiotic contamination has garnered significant attention,particularly given the growing pressures from aquaculture,a key contributor to environmental antibiotic loads.Addressing both antibiotic and nitrogen pollution in such ecosystems is critical.In this study,the aerobic denitrifying bacterium Marinobacter hydrocarbonoclasticus RAD-2,previously isolated in our laboratory,was subjected to a series of concentration gradients(0,20,40,60,80,100 mg/L)to evaluate the single and combined effects of tetracycline(TET)and chlortetracycline(CTC)on the aerobic denitrification process.Among them,the combined effects of antibiotics were set up in a full-factor experimental design(a total of 30 treatment combinations)on the basis of the single-factor experiments of TET and CTC.Results demonstrated that the inhibitory impact of both antibiotics intensified with increasing concentration,with CTC exerting a more pronounced inhibitory effect.Notably,RAD-2 was unable to proliferate at 100 mg/L of TET or 80 mg/L of CTC.High concentrations of either antibiotic significantly suppressed the expression of key denitrification functional genes,including nirX,napA,norB,and nosZ.Furthermore,simultaneous exposure to both antibiotics led to a rapid decline in nitrogen removal efficiency(TET or CTC>60 mg/L),alongside substantial inhibition of bacterial growth and functional gene expression,except for napA.Under specific concentration ranges,the combination of TET and CTC exhibits a certain degree of antagonistic effect.These findings provide critical insights into the restoration of wetland ecosystem health and inform strategies to mitigate the dual challenges of antibiotic and nitrogen pollution in aquaculture effluents.
基金supported financially by the National Natural Science Foundation of China(31811530297 and 32170217).
文摘Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.
